One of the most problematic aspects of traveling between mainland China and Hong Kong is the car travel: People in the former drive on the right side of the road; people in the latter drive on the left (a vestige of the British empire). So to quell confusion at the border and, more importantly, to keep cars from smashing into each other, the Dutch firm NL Engineers proposed a brilliant, simple solution, the Flipper bridge.
The bridge does exactly what the name suggests: It flips traffic around. The key here is separating the two sides of traffic, using a figure-eight shape. One side of the road dips under the other, funneling cars that were traveling on the left to the right (and vice versa), without forcing them to encounter head-on traffic at an intersection. The bridge makes what should be a disorienting switch exquisitely easy.
